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Additional menu symbols could help diners know when to slow down, stop

José Martinez

Researchers added traffic light symbols that represented calorie ranges to menus that already contained calorie counts, and found that the symbols appeared to help reduce calorie consumption, whether or not the diner was particularly health-conscious. Scott Olson/Getty Images

Some with calorie counts next to each item, per the federal government's proposed rule under the Affordable Care Act.

Some with calorie counts and a symbol – in this case, a traffic signal – where red, yellow and green "lights" indicate different calorie count ranges, from high to low.

"What we found is that the menu labels that had the calories and traffic light symbols were the most effective in reducing calories," said Brenna Ellison, a professor of agricultural and consumer economics at the University of Illinois at Urbana-Champaign and co-author of the study. In fact, the symbol/calorie count combination reduced the content of people's entrees by an average of more than 100 calories.

But then, said Ellison, "the effect was reduced."

People decided to reward themselves for getting a "green-light" entree, whether it was with a soda or dessert. So the net reduction resulting from the symbol/calorie count menu was actually closer to 70, and Ellison noted you can reduce about twice as many calories by simply skipping a soda.

But there's a cumulative effect to consider, she said. "If this effect was to persist every time you went out to eat, maybe that could add up to a few pounds of weight loss per year," she explained.

The people reading the menus also mattered, wrote the authors:

[Both the calorie count and the symbol/calorie count labels] were more effective among the least health conscious – precisely the people that menu labeling laws are often trying to influence. Moreover, our results suggest the [symbol/calorie count] menu was more effective than the calorie-only menu at reducing entrée calories ordered as health consciousness increased.

In other words, either label was effective with folks who aren't overtly health-conscious, and the symbol/calorie count menus were effective in further reducing calorie consumption among even the most health-conscious of patrons.

Ellison did mention a slight problem with the traffic light menu: People didn't like it.

"Even though the traffic light was most effective, it was the least popular," she said. "In fact, people prefer just the calories. That suggests to us that people want information but they don't want to be told what's good or bad for them."